The present invention relates to the manufacture of ophthalmic lenses. In particular, the invention provides deformable molds and methods for manufacturing ophthalmic lenses using deformable molds.
The use of ophthalmic lenses, including spectacle lenses, contact lenses, intraocular lenses, and the like for the correction of ametropia is well known. Production of the lenses requires the use of molds that impart the desired corrective characteristics onto the lens surfaces. Typically, a large inventory of molds is required corresponding to each sphere, add, and cylinder power, and combinations thereof desired for the finished lens. Production and maintenance costs for the mold inventory are high.
One method for production of lenses that attempts to eliminate the need for large inventory molds is disclosed in U.S. Pat. No. 6,026,204. In this patent is disclosed the use of customized, heated dies, which utilize mechanical fingers, alone or in combination with a metal surface, to impart the desired corrective characteristics to a lens blank. This method is disadvantageous in that it is unsuitable for the production of certain ophthalmic lenses, such as soft contact lenses because soft contact lens materials are thermoset materials that cannot be deformed with heat. Additionally, this method is disadvantageous in that molding the lens material using a heated die requires that the lens blanks"" optical axis be perfectly aligned with that of the die, which adds a great degree of difficulty to production of the lens. Finally, the disclosed method is not the most cost effective production method in that it is a thermal molding process. Therefore, a need exists for a method to produce ophthalmic lenses with a mold that permits reduction of lens inventory and which overcomes some or all of these disadvantages.